My guesstimate is that due to the growing use of analytics, the value of speed wide receivers might continue to decline (it might also be a reason for increased interest in high contested catch rate receivers).
The reason for this is when you look at the analytics, it is much better to force a team to make as many first downs as possible to score.
As such, teams might play more and more two high shell and other over the top defensive alignments.
The data I have seen shows that the probability of getting a first down from 1st and 10 is 66%.
Based on this, every additional first down required to score reduces the probability of the next first down by 33%, as shown in the table below.
.
This is also the math behind what makes chunk plays (20 plus yards), which reduce the number of first downs required to score, so big.